We asked the BuzzFeed Community to tell us their family's biggest secrets. Here are the completely jaw-dropping results.

1.This diabolical plan:

"After my uncle died, we discovered that he had a second wife who he spent most of his time with. Literally no one on either side knew this for over 25 years. He also purchased the same prefab house, same furniture, and same everything for each of his wives so their houses mirrored each other (and probably helped him to keep his story straight)."

2.This chilling testimony:

"My husband's grandmother was a Jewish teenager during WWII and was placed into a concentration camp. During this time, a Nazi guard fell in love with her and would bring her extra food, clothing, etc. He continued to protect her to keep her alive. When the war was over, she came to the US and started a new life. She told this secret to our family just days before she passed away."

3.This insane story:

4.This wild tale:

"My great-uncle was killed in a train accident in the '60s. I recently learned that he was having an affair at the time, and he got killed because he and his mistress were fooling around while they were parked on a railroad track! The train crashed right into them. No one in my family has ever really discussed it."

5.This late confession:

"My dad created a Ponzi scheme of sorts by claiming he created an invention that turned water into energy. He defrauded thousands of people out of their money. When my dad ultimately went to prison, we believed it was just a mistake (not knowing where his money was really coming from), but a few months ago my mom revealed that he went to prison for a similar crime before I was born."

—Dallas Brady, Facebook

ABC

6.This life-changing secret:

"I spent the last 40 years obsessing over my grandmother’s amazing family photo collection, which showcased our rich, dynamic, and loving family history. Well, last year she pulled out a secret photo album, containing several photos of my great-great-uncle, proudly posing in his SS Nazi uniform. I felt like my entire family history was a lie."

8.This detective case:

"My brother and his ex-wife were swingers, and she happened to get pregnant. Ever since their daughter was born, we've had a family friend who always – I mean always – came to the child's big life events, like birthdays and recitals. It wasn't until recently when someone pointed out how similar that child and our family friend look. I’ve tried asking questions, but no one will give me a straight answer, so I’m convinced she’s not my brother's kid!"

9.This bizarre turn:

10.This riveting piece:

"My mom revealed that our Dutch ancestors hid a Jewish family in their attic and forged food stamps during WWII. If they were caught, they would have been killed, so it stayed a secret for a long time. No one in my family knew what happened to the Jewish family after the war. I hope they survived."

—Sasha Bee, Facebook

11.This heartbreaking saga:

"My great-grandmother's brother married a woman who always looked extremely put together – perfect makeup and hair, etc. When she was on her deathbed, she admitted that she was actually black (albeit fairly light-skinned). She 'disguised' herself using makeup and hair relaxers because she couldn't have legally married her white husband as a black woman, and she never felt that their love would be accepted unless she was able to pass. Of course her husband knew, but no one else in the family did. No one was mad when they found out, which might have been the saddest part. The two never had children, and my great-grandma's brother never remarried."

—Mandy Caruso, Facebook

NBC

12.This gripping adventure:

"My uncle had an affair with his oldest son's wife. To this day, we still don't know if the two kids the wife had are my cousin's or my uncle's."

13.This undisclosed information:

"My grandma was kidnapped when she was 12. She was ultimately returned two days later, but everyone pretended like nothing had happened, including her own mother. Everyone refused to talk about it, even to this day. It's so sketchy."

14.This crazy occurrence:

15.And this DNA twist:

"I recently found out by accident via a 23andMe DNA test that I'm not my dad's biological child. Apparently my parents broke up for a few months years ago, and my mom got pregnant. She didn't find out she was pregnant until after she got back together with my dad, so she decided not to say anything."